Climate change, the one to blame for the reduced oceanic oxygen levels due to rising global temperature
You may be thinking, “Here we are again, talking about climate change”. Yes, I will be one of those people who will be talking about this issue again, and again, and again, until we all see some actual progress regarding this issue. I am not here to convince you that climate change is real. Climate change is indeed a real problem and it is causing a decrease in oceanic oxygen levels. We need to start talking about this.
Dr. Ralph Keeling and his colleagues at the University of California found that with rising temperature levels, a reduced solubility of oxygen molecules is observed in the ocean. Dr. Keeling and his team’s ocean models predicted that there will be about 1-7% decrease in oceanic oxygen levels in the next century.
How does this affect us and the aquatic life? Most marine organisms use cellular respiration, a process that converts organic molecule and oxygen to a sustainable form of energy and carbon dioxide as a by-product. The equation for cellular respiration is shown below:
This image shows cellular respiration: a process that converts an organic molecule to energy (ATP) (Image by Jolean Endique).
Algae and planktons are the most abundant photosynthetic organisms in the ocean. They need both light energy and nutrients to produce oxygen and capture CO2 in the atmosphere. With decreasing oxygen levels, cellular respirators may be unable to provide a sufficient amount of nutrients for photosynthetic organisms. As you may have thought, yes, our chance of increasing our oxygen levels and decreasing our atmospheric CO2 may be very slim. In addition, a decrease in marine productivity may also take a toll on fisheries and coastal economies that solely depend on aquatic fauna. As phrased by Dr. Breitberg, a marine ecologist at the Smithsonian Environmental Research Center, about coral reef bleaching as a result of low oceanic oxygen levels, “As seas are losing oxygen, those areas are no longer habitable by many organisms”.
Coral reef bleaching is another consequence of reduced oceanic oxygen levels. The sensation it gives to coral reefs is like “ripping your guts out” as described by Mark Eakin, coordinator of the Coral Reef Watch program for the U.S. National Oceanic and Atmospheric Administration. This occurs as the very crucial microscopic algae living inside the coral reefs are being affected by bleaching the most. Coral bleaching is caused both by ocean acidification and reduced oxygen levels. However, when the temperature rises 2 degrees above the normal highest temperatures of a certain area, coral bleaching then becomes completely caused by warmer waters. This is also the reason why most coral reefs nowadays are not as colorful as they were.
This image is a snapshot from a video showing a comparison of how the same corals used to be a year ago at Iriomote, Southern Japan and how they look now due to coral bleaching (Source: The Hydrous Youtube Channel).
We now know some of the drastic effects of reduced oceanic oxygen levels due to climate change. But, how long will it take for us to take action against climate change? How long do we have until we call Earth inhabitable? We need to stop the factors that contribute to climate change as soon as possible. We need to be better at segregating our wastes, biodegradable from non-biodegradable from plastics. We need to find better alternatives to fossil fuels, some better source of renewable energy, to reduce our carbon emissions. We need to stop hurting our forests and taking the life out of them. All of these will slow down global warming and prevent climate change from ruining our beautiful world. Let’s save our planet from dying. Not only the ocean is affected, each and every one of us is.
